Solar-assisted Post-combustion Carbon Capture feasibility study

Abstract

Solvent-based Post-combustion Carbon Capture (PCC) is one of the promising technologies for reducing CO 2 emissions from existing fossil-fuel power plants due to ease of retrofitting. A significant obstacle in widely deploying this technology is the power plant output reduction (Output Power Penalty – OPP) due to the energy intensive CO 2 separation process. In this paper we propose and theoretically evaluate a system to reduce the OPP by providing part of the PCC energy input using solar thermal energy. It is hypothesized that reducing the OPP during the daytime coincides with peaks in wholesale electricity prices thus increasing the revenue stream for a solar-assisted PCC (SPCC) plant. The general framework for assessing and sizing an SPCC system is presented. A techno-economic assessment is performed as a case study for a 300 MW e pulverized coal power plant in New South Wales, Australia using actual weather and wholesale electricity price data. It is shown that the proposed technology can be economically viable for solar collector costs of US$100/m 2 at current retail electricity prices and optimal Solar load-Fraction (SF) of 22% (SF is the portion of solvent regeneration energy provided by solar energy). The convergence of increasing electricity prices and decreasing collector costs improves SPCC viability at higher SF.